Bank-driven model for preventing double spending of digital currency coexisting on multiple DLT networks

ABSTRACT

A system and method for preventing the double-spending of digital currency that transfers between multiple DLT networks. The system and method includes creating, based on a unit of fiat currency, a first digital currency of a first type on a first DLT network and a second digital currency of a second type on a second DLT network. Each of the first digital currency and the second digital currency simultaneously represent a value associated with the unit of fiat currency. The system and method includes detecting a transaction request to transfer the first digital currency from the first DLT network to the second DLT network. The system and method include locking, responsive to detecting the transaction request, the first digital currency onto the first DLT network to prevent a transfer of the first digital currency from the first DLT network to another DLT network responsive to a subsequent transaction request.

BACKGROUND

Digital currency (also referred to as, “digital money”, “electronicmoney”, or “electronic currency”) is a type of currency available indigital form, as opposed to physical currency, such as banknotes andphysical coins. It exhibits properties similar to physical currencies,but can allow for instantaneous transactions and borderlesstransfer-of-ownership. Examples of digital currency include virtualcurrencies, cryptocurrencies, and central bank digital currency. Thesecurrencies may be used to buy physical goods and services, but may alsobe restricted to certain communities such as for use inside an onlinegame and/or software application.

SUMMARY

Aspects of the present disclosure relate generally to distributed ledgertechnology in the field of cryptocurrency, and more particularly tosystems and methods for preventing the double-spending of digitalcurrency that transfers between multiple distributed ledger technology(DLT) networks.

One aspect disclosed herein is directed to a method for preventing thedouble-spending of digital currency that transfers between multiple DLTnetworks. In some arrangements, the method includes creating, based on aunit of fiat currency, a first digital currency of a first type on afirst DLT network and a second digital currency of a second type on asecond DLT network. In some arrangements, each of the first digitalcurrency and the second digital currency simultaneously represent avalue associated with the unit of fiat currency for at least a period oftime. In some arrangements, the method includes detecting a transactionrequest to transfer the first digital currency from the first DLTnetwork to the second DLT network. In some arrangements, the methodincludes locking, responsive to detecting the transaction request, thefirst digital currency onto the first DLT network to prevent a transferof the first digital currency from the first DLT network to another DLTnetwork responsive to a subsequent transaction request.

In another aspect, the present disclosure is directed to a system forpreventing the double-spending of digital currency that transfersbetween multiple DLT networks. In some arrangements, the system includesone or more processors; and one or more computer-readable storagemediums storing instructions which, when executed by the one or moreprocessors, cause the one or more processors to create, based on a unitof fiat currency, a first digital currency of a first type on a firstDLT network and a second digital currency of a second type on a secondDLT network. In some arrangements, each of the first digital currencyand the second digital currency simultaneously represent a valueassociated with the unit of fiat currency for at least a period of time.In some arrangements, the system includes one or more processors and oneor more computer-readable storage mediums storing instructions which,when executed by the one or more processors, cause the one or moreprocessors to detect a transaction request to transfer the first digitalcurrency from the first DLT network to the second DLT network. In somearrangements, the system includes one or more processors and one or morecomputer-readable storage mediums storing instructions which, whenexecuted by the one or more processors, cause the one or more processorsto lock, responsive to detecting the transaction request, the firstdigital currency onto the first DLT network to prevent a transfer of thefirst digital currency from the first DLT network to another DLT networkresponsive to a subsequent transaction request.

One aspect disclosed herein is directed to a method for preventing thedouble-spending of digital currency that transfers between multiple DLTnetworks. In some arrangements, the method includes creating, by a nodeof a first DLT network, a first digital currency of a first type on thefirst DLT network, the first digital currency associated with a seconddigital currency of a second type on a second DLT network. In somearrangements, the method includes intercepting, by the node of the firstDLT network, a transaction request to transfer the first digitalcurrency from the first DLT network to the second DLT network. In somearrangements, the method includes locking, by the node of the first DLTnetwork responsive to intercepting the transaction request, the firstdigital currency onto the first DLT network to prevent a transfer of thefirst digital currency from the first DLT network to another DLT networkresponsive to a second transaction request. In some arrangements, themethod includes determining, by the node of the first DLT network, apresence or an absence of the second digital currency on the second DLTnetwork.

In another aspect, the present disclosure is directed to anon-transitory computer-readable storage medium storing instructionswhich, when executed by one or more processors, cause the one or moreprocessors to perform operations including creating, based on a unit offiat currency, a first digital currency of a first type on a first DLTnetwork and a second digital currency of a second type on a second DLTnetwork. In some arrangements, each of the first digital currency andthe second digital currency simultaneously represent a value associatedwith the unit of fiat currency for at least a period of time. In somearrangements, the non-transitory computer-readable storage mediumstoring instructions which, when executed by one or more processors,cause the one or more processors to perform operations includingdetecting a transaction request to transfer the first digital currencyfrom the first DLT network to the second DLT network. In somearrangements, the non-transitory computer-readable storage mediumstoring instructions which, when executed by one or more processors,cause the one or more processors to perform operations includinglocking, by the one or more processors responsive to detecting thetransaction request, the first digital currency onto the first DLTnetwork to prevent a transfer of the first digital currency from thefirst DLT network to another DLT network responsive to a subsequenttransaction request.

These and other features, together with the organization and manner ofoperation thereof, will become apparent from the following detaileddescription when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a block diagram depicting an example environment systems andmethods for preventing the double-spending of digital currency thattransfers between multiple DLT networks, according to some arrangements.

FIG. 2A is a block diagram depicting an example exchange node of theenvironment in FIG. 1 , according to some arrangements.

FIG. 2B is a block diagram depicting an example DLT node of theenvironment in FIG. 1 , according to some arrangements.

FIG. 3 is a flow diagram depicting a method for preventing thedouble-spending of digital currency that transfers between multiple DLTnetworks from the perspective of an exchange node, according to somearrangements.

FIG. 4 is a flow diagram depicting a method for preventing thedouble-spending of digital currency that transfers between multiple DLTnetworks from the perspective of a DLT node, according to somearrangements.

Like reference numbers and designations in the various drawings indicatelike elements.

DETAILED DESCRIPTION

A cryptocurrency (or crypto currency) is a digital currency designed towork as a medium of exchange that uses strong cryptography to securefinancial transactions, control the creation of additional units, andverify the transfer of assets. Cryptocurrencies use decentralizedcontrol as opposed to centralized digital currency and central bankingsystems. The decentralized control of each cryptocurrency works throughdistributed ledger technology (DLT), such as a blockchain, that servesas an electronic public financial transaction database

Cryptocurrency users store their cryptocurrency in digital wallets,where the purchase, sale, and exchange transactions occur in blocks.Each block connects to the previous block by means of a code, based onBlockchain technology. A cryptocurrency runs on a blockchain, which is ashared ledger or document duplicated several times across a network ofcomputers (“nodes”). The updated document is distributed and madeavailable to all nodes on the blockchain. Every single transaction made,and the ownership of every single cryptocurrency in circulation, isrecorded in the blockchain. As such, the nodes of the blockchain or DLTnetwork can prevent invalid transactions from taking place.

However, transferring digital currency such as a cryptocurrency betweenmultiple DLT networks creates problems that the digital currency (orcryptocurrency) industry has yet to solve. Firstly, a DLT networkoperating a first type of cryptocurrency (e.g., Bitcoin) cannotcommunicate with a DLT network operating a second type of digitalcurrency (e.g., Ethereum) due to at least their incompatiblecommunication protocols. Furthermore, even if the DLT networks couldcommunicate with one another, there is no mechanism for preventing thedouble-spending of the digital currency as it traverses across thenetworks because each network (and its respective nodes) manages anentirely different electronic ledger. As such, the nodes of one DLTnetwork would be unable to verify and concretize the transactions ofcryptocurrencies involving another DLT network.

Accordingly, the present disclosure is directed to systems and methodsfor preventing the double-spending of digital currency that transfersbetween multiple DLT networks. The multiple types of digital currencyare created and mirrored based on the same collateral (also referred toherein as, “single-collateral”), such that they coexist on multiple DLTnetworks. An exchange node converts and/or exchanges a digital currencyof a first type on a first DLT network to a digital currency of a secondtype on a second DLT network. The exchange node can then delete/destroythe digital currency of the first type on the first DLT network, or theDLT networks can directly communicate with one another via a singleprotocol to agree upon the destruction of mirrored/duplicative digitalcurrency.

In general, as described in the below passages and specifically in thedescription of FIG. 1 , an issuer (e.g., issuer 140 in FIG. 1 ) mayoperate an exchange node (e.g., exchange node 130 in FIG. 1 ) that hostsan exchange network for participating in transactions occurring betweena plurality of Distributed Ledger Technology (DLT) networks (e.g., DLTnetworks 102, 104, 106 in FIG. 1 ) or blockchain networks. Each DLTnetwork is associated with a digital currency or cryptocurrency of aparticular type (e.g., Bitcoin, Ether, XRP, etc.) and includes aplurality of DLT nodes (also referred to herein as, “nodes”) that areinterconnected with one another to form a peer-to-peer network. Theexchange network and the plurality of DLT networks are interconnectedwith one another via a communication network (e.g., communicationnetwork 120 in FIG. 1 ).

To begin, the exchange node adds any number of DLT networks (e.g., theBitcoin network, the Ethereum network, the Ripple network, etc.) thatare each associated with a particular type of digital currency (e.g., aBitcoin for the Bitcoin network, an Ether for the Ethereum network, anXRP for the Ripple network, etc.) to the exchange network in response toreceiving a request from any of the DLT networks. For example, a node(e.g., any one of nodes 103 a-103 d in FIG. 1 ) of a “first” DLT network(e.g., DLT network 102 in FIG. 1 ) associated with a “first” type ofdigital currency (e.g., a Bitcoin) may send a request to the exchangenode to join the exchange network. In response to receiving the request,the exchange node adds the first DLT network to the exchange network bygenerating and sending a message to a node (e.g., the requesting node, anormal node, a master node) of the first DLT network to cause the nodeto grant permission for the exchange node to detect (e.g., monitor) thetransaction requests that are sent by and/or received by a node of thefirst DLT network. The message also includes program code (e.g., ascript, an executable) that, when executed by the node of the first DLTnetwork, causes the node to install one or more monitoring agents (e.g.,monitoring agent 150 in FIG. 1 ) on any or all of the nodes included inthe first DLT network to allow the exchange node to detect an occurrenceof such transaction requests. In some arrangements, a monitoring agentthat is installed on a node may be configured to intercept thetransaction requests that are sent by and/or received by the node, andredirect the transaction request (or a copy of the transaction request)to the exchange node. In some instances, the message may include a smartcontract, that when executed by the node, causes the node tomonitor/detect (or allow the exchange node to monitor/detect) thetransactions that are made by the node. In some arrangements, themessage may include program code that, when executed by the node of thefirst DLT network, causes the node to install one or more “hooks” thataugment the behavior of an operating system and/or application (e.g., adigital wallet, a transaction ledger, etc.) executing on the node byintercepting function calls, messages, and/or events passed between theoperating system and/or application, and redirecting the interceptedfunction calls, messages, and/or events to the exchange node.

Continuing with the example, a node (e.g., any one of nodes 105 a-105 din FIG. 1 ) of a “second” DLT network (e.g., DLT network 104 in FIG. 1 )associated with a “second” type of digital currency (e.g., an Ether) mayalso send a request to the exchange node to join the exchange network.In response to receiving the request from the second DLT network, theexchange node repeats the same process as discussed above with respectto the first DLT network, but with respect to the second DLT network.That is, the exchange node adds the second DLT network to the exchangenetwork by generating and sending a message to a node (e.g., therequesting node, a normal node, a master node) of the second DLT networkto cause the node to grant permission for the exchange node to detect(e.g., monitor) the transaction requests that are sent by and/orreceived by the second DLT network. The message also includes programcode (e.g., a script, an executable) to cause the node to install one ormore monitoring agents (e.g., monitoring agent 152 in FIG. 1 ) on any orall of the nodes included in the second DLT network to allow theexchange node to detect an occurrence of such transaction requests.

The exchange node then creates (e.g., mirrors, copies, etc.) multipletypes of digital currency based on the same collateral for each of theDLT networks that were added to the exchange network. For example, theexchange node creates a digital currency of the first type (e.g.,Bitcoin) on the first DLT network (e.g., a Bitcoin network) based on aunit of fiat currency (e.g., fiat currency 142 in FIG. 1 ) held by theissuer, and a digital currency of the second type (e.g., an Ether) onthe second DLT network (e.g., an Ethereum network) based on the sameunit of fiat currency. As such, the first currency created on the firstDLT network and the second currency created on the second DLT networkwill simultaneously represent (e.g., on each of their respective DLTnetworks) the same unit of fiat currency that is held by the issuer forat least a period of time (e.g., milliseconds, seconds, minutes, hours,days, months, etc.). As a result, the digital currencies are considered“mirrored” and coexisting on the DLT networks, such that they are eachavailable to be involved in a transaction. The exchange node alsoassigns and/or attaches a common serial number to each of the digitalcurrency to indicate that the digital currency, despite existing onmultiple DLT networks, were created from the same collateral.

The exchange node then monitors the communication to and/or from any ofthe DLT networks that have been added to the exchange network forrequests (also referred to herein as, “a transaction request”) totransfer a digital currency between nodes of the same DLT networks, aswell as between nodes of different DLT networks. For example, the firstDLT network may send a request (e.g., transaction request in FIG. 1 ) totransfer the first digital currency (e.g., a Bitcoin) from the first DLTnetwork to the second DLT network. The exchange node detects thetransaction request via the one or more monitoring agents that werepreviously installed on the first DLT network (e.g., installed on one ormore nodes of the first DLT network) on behalf of the exchange node, orby receiving a copy of the transaction request that was redirected bythe one or more “hooks” that were previously installed on the first DLTnetwork on behalf of the exchange node. In response to detecting thetransaction request, the exchange node locks (e.g., secures, freezes,suspends, etc.) the first digital currency onto the first DLT network toprevent a transfer of the first digital currency from the first DLTnetwork to the second DLT network or any another DLT network (e.g., DLTnetwork 106 in FIG. 1 ) responsive to a subsequent transaction requestinvolving the first digital currency.

As discussed above, in some instances (not all), DLT networks that areassociated with different types of digital currency may be unable todirectly communicate with one another due to incompatible communicationprotocols. The exchange node, however, may bridge the communicationbetween the DLT networks by translating their messages from onecommunication protocol to another communication protocol. Thus, byfunctioning as a “trusted intermediary”, the exchange node may be ableto detect when a DLT network makes a transaction request to another DLTnetwork by monitoring the exact communication it has already beenassigned to translate.

After locking the digital currency, the exchange node sends aconfirmation request to the second DLT network to cause the second DLTnetwork to confirm whether the transaction has completed. For example, anode of the second DLT network may search the second DLT network for thesecond digital currency that is associated with the first digitalcurrency based on matching the serial number that is common to eachdigital currency. If the second digital currency does not exist on thesecond DLT network, then the second DLT sends a confirmation to theexchange node to indicate that the transaction has not been completedbecause the second digital currency was not found, which in turn, causesthe exchange node to unlock the first digital currency from the firstDLT network and send a message to the first DLT network to indicate thatthe transaction was denied by the second DLT network. However, if thesecond digital currency does exist on the second DLT network, then thesecond DLT sends a confirmation back to the first DLT network toindicate that the transaction had been completed because the seconddigital currency was found, which in turn, causes the exchange node todestroy the first digital currency on the first DLT network. In somearrangements, instead of relying on communication from the second DLTnetwork, the exchange node may search the second DTL network for thesecond digital currency. In some arrangements, the exchange node maykeep (maintain, preserve, etc.) the first digital currency locked to thefirst DLT network instead of destroying the first digital currency,thereby allowing the second DLT network to transfer the second digitalcurrency back to the first DLT network if requested via a secondtransaction request.

Thus, the exchange node is able to prevent the double spending of thefirst digital currency as a result of a subsequent transaction bylocking the first digital currency onto the first DLT network until thefirst transaction is either approved/completed or denied/canceled.

FIG. 1 is a block diagram depicting an example environment forpreventing the double-spending of digital currency that transfersbetween multiple DLT networks, according to some arrangements. Theenvironment 100 includes DLT networks 102, 104, 106 that are eachassociated with a digital currency or cryptocurrency of a particulartype in that each DLT network 102, 104, 106 hosts a public ledger thatis governed by source code consisting of cryptologic and/or algorithmicprotocols. DLT network 102 is associated with digital currency 110, DLTnetwork 104 is associated with digital currency 112, and DLT network 106is associated with digital currency 114. Each digital currency maymaintain a locked or unlocked state. For example, as shown in FIG. 1 ,digital currency 110 is in an unlocked state, digital currency 112 is ina locked state (shown as locked digital currency 116), and digitalcurrency 114 is in an unlocked state. Although FIG. 1 shows digitalcurrency 110 as an Ether for an Ethereum network, digital currency 112as a Bitcoin for a Bitcoin network, and digital currency 114 as an XRPfor the Ripple network, it will be appreciated by those skilled in theart that DLT networks 102, 104, 106 may be any type of DLT network. Assuch, digital currencies 110, 112, 114 may be any type of digitalcurrency that is supported by the corresponding DLT network.

Each DLT network 102, 104, 106 includes a plurality of nodes that areinterconnected with one another to form a peer-to-peer network. As shownin FIG. 1 , the DLT network 102 includes nodes 103 a, 103 b, 103 c, 103d (collectively referred to herein as, “nodes 103”) that areinterconnected with one another to form a “first” peer-to-peer network;the DLT network 104 includes nodes 105 a, 105 b, 105 c, 105 d(collectively referred to herein as, “nodes 105”) that areinterconnected with one another to form a “second” peer-to-peer network;and the DLT network 106 includes nodes 107 a, 107 b, 107 c, 107 d(collectively referred to herein as, “nodes 107”) that areinterconnected with one another to form a “third” peer-to-peer network.While in some examples the environment 100 is described as including thefirst, second, and third peer-to-peer networks, in various otherexamples, more or less than three networks may be included.

The environment 100 also includes an exchange node 130 that hosts anexchange network for participating in transactions occurring between anyof the nodes of the DLT networks 102, 104, 106. The exchange network andthe DLT networks 102, 104, 106, are interconnected with one another viaa communication network (e.g., communication network 120 in FIG. 1 ).Each of the DLT networks 102, 104, 106; the nodes 103, 105, 107; and theexchange node 130 include hardware elements, such as one or moreprocessors, logic devices, or circuits.

As shown in FIG. 1 , the exchange node is a separate entity from each ofDLT networks 102, 104, 106. That is, the exchange node resides andexecutes outside of DLT network 102, 104, 106. In some arrangements, theexchange node may optionally execute on or within at least one of DLTnetworks 102, 104, 106.

The DLT networks 102, 104, 106 may be associated with the same ordifferent types of digital currency. For example, the DLT network 102may be a Bitcoin network that host a public ledger associated with aBitcoin, the DLT network 104 may be an Ethereum network that hosts apublic ledger associated with an Ether, and the DLT network 106 may be aRipple network that hosts a public ledger associated with an XRP. Asanother example, each DLT network 102 may be a Bitcoin network thathosts a public ledger associated with a Bitcoin.

A node (e.g., nodes 103 a-d, nodes 105 a-d, nodes 107 a-d) is anelectronic computing device that is capable of conducting digitalcurrency transactions (e.g., shown in FIG. 1 as “transaction requests”)with another node. The transactions that are performed by the nodes on aparticular DLT network are recorded in an electronic transaction ledger(e.g., transaction ledger 218B in FIG. 2B). Each node may store andbroadcast copies of the electronic transaction ledger to neighboringnodes to ensure that each node in the DLT network may be able tovalidate the transactions that occur on the DLT network via a set ofconsensus rules. Each node is also capable of sending a join request(shown in FIG. 1 as “join requests”) to the exchange node 130 to jointhe exchange network. Each node is also capable of receiving a message(e.g., shown in FIG. 1 as, “monitoring agent setup command”) to installa monitoring agent onto the node and/or the DLT network associated withthe node to allow the exchange node to monitor/detect the transactionsthat are made by the node. For example, node 103 a may install one ormore monitoring agents 150 on any of the nodes (including itself)associated with DLT network 102; node 105 a may install one or moremonitoring agents 152 on any of the nodes (including itself) associatedwith DLT network 104; and node 107 a may install one or more monitoringagents 154 on any of the nodes (including itself) associated with DLTnetwork 106. Although FIG. 1 shows monitoring agent 150 executing onnode 103 a, a monitoring agent 150 may be installed on any other node(e.g., node 103 b, node 103 c, node 103 d) associated with DLT network102. Although FIG. 1 shows monitoring agent 152 executing on node 105 a,a monitoring agent 152 may be installed on any other node (e.g., node105 b, node 105 c, node 105 d) associated with DLT network 104. AlthoughFIG. 1 shows monitoring agent 154 executing on node 105 a, a monitoringagent 154 may be installed on any other node (e.g., node 107 b, node 107c, node 107 d) associated with DLT network 106.

In some instances, the message (e.g., shown in FIG. 1 as, “monitoringagent setup command”) may include a smart contract, that when executedby the node, causes the node to monitor/detect (or allow the exchangenode to monitor/detect) the transactions that are made by the node. Eachnode is also capable of sending a transaction confirmation (e.g., shownin FIG. 1 as, “transaction confirmation”) to the exchange node 130indicating whether a transaction has completed. Each node is alsocapable of receiving a message (e.g., shown in FIG. 1 as, “lock/unlockcommand”) from the exchange node 130 to lock or unlock a digitalcurrency to/from the DLT network of the node. Each node is also capableof receiving a message (e.g., shown in FIG. 1 as, “coin creationcommand”) to create/add a digital currency onto the DLT network of thenode. For example, the message may add an entry to the electronictransaction ledger of the node. Each node is also capable of receiving amessage (e.g., shown in FIG. 1 as, “coin destruction command”) todestroy/remove a digital currency from the DLT network of the node. Forexample, the message may remove an entry from the electronic transactionledger of the node. The other nodes in the DLT network become aware ofthe newly created digital currency or newly destroyed digital currencywhen the node, during the electronic ledger reconciliation process,broadcasts its electronic transaction ledger to its neighboring nodes.

A node may be any number of different types of electronic computingdevices (also referred to herein as, “computing device” and “electronicdevice”) adapted to communicate over a communication network 120,including without limitation, a digital wallet (also known as an“e-Wallet”), a personal computer, a laptop computer, a desktop computer,a mobile computer, a tablet computer, a smart phone, an applicationserver, a catalog server, a communications server, a computing server, adatabase server, a file server, a game server, a mail server, a mediaserver, a proxy server, a virtual server, a web server, or any othertype and form of computing device or combinations of devices.

As used herein, a node may be a “normal” node” or as a “master node”.While a normal node and a master node are both electronic computingdevices, a master node (also known as a “super node”) differs from anormal node in that a master node has more computing resources (e.g.,computing power, memory resources, networking bandwidth, storage space,etc.) than a normal node. Next to validating, saving and broadcastingtransactions (which are the same operations performed by a normal node),a master node may also facilitate other events on the DLT network, suchas governing voting events, providing execution of protocol operations,and enforcing the laws of the corresponding DLT network. Unlike a normalnode, a master node may also maintain a constant, active connection withone or more nodes of the DLT network. As such, a master node generallyrequires much more resources (e.g., electricity, up-time, maintenance,storage space, memory) than a normal node.

An exchange node 130 is an electronic computing device that monitors thetransaction requests sent between nodes of the same DLT network and/ornodes of different DLT networks. The exchange node 130 is also capableof receiving a join request (shown in FIG. 1 as “join requests”) from anode to join an exchange network (not shown in FIG. 1 ) that is managed(hosted) by the exchange node 130. The exchange node 130 is also capableof sending a message (e.g., shown in FIG. 1 as, “monitoring agent setupcommand”) to install a monitoring agent onto a node and/or the DLTnetwork associated with the node. The exchange node 130 is also capableof receiving a transaction confirmation (e.g., shown in FIG. 1 as,“transaction confirmation”) from a node indicating whether a transactionbetween nodes has completed. The exchange node 130 is also capable ofsending a message (e.g., shown in FIG. 1 as, “lock/unlock command”) to anode to lock or unlock a digital currency to the DLT network of thenode. The exchange node 130 is also capable of sending a message (e.g.,shown in FIG. 1 as, “coin creation command”) to a node to create/add adigital currency onto the DLT network of the node. For example, themessage may create/add an entry to the electronic transaction ledgerassociated with the DLT network of the node. The exchange node 130 isalso capable of sending a message (e.g., shown in FIG. 1 as, “coindestruction command”) to a node to destroy/remove a digital currencyfrom the DLT network of the node. For example, the message maydestroy/remove an entry from the electronic transaction ledgerassociated with the DLT network of the node. As discussed above, theother nodes in the DLT network update their respective electronictransaction ledgers to show the newly added digital currency or newlydestroyed digital currency when the node, during the electronic ledgerreconciliation process, broadcasts its electronic transaction ledger toits neighboring nodes.

The environment 100 includes an issuer 140 that develops, registers, andsells securities for the purpose of financing its operations. The issuer140 may be a corporation, a bank, an investment trust, or a domestic orforeign government. The issuer 140 may make available the followingtypes of securities: common and preferred stocks, bonds, notes,debentures, bills and derivatives. The issuer 140 maintains (e.g.,stores) fiat currency 142 on behalf of an account holder of the issuer140. The issuer 140 includes any number of electronic computing devices(not shown in FIG. 1 ) for the purpose of operating/managing theexchange node 130, and for communicating with any other electroniccomputing device that is connected to the communication network 120.

Fiat currency 142 (also referred to herein as, “fiat money”) money isthe currency that a government has declared to be legal tender, but itis not backed by a physical commodity. The value of each country's fiatcurrency is determined by the supply of the currency and the demand forit to purchase goods and services. Fiat currencies 142 are backed by thecredit of the economy and taxing authority of the government that issuesit, as well as the faith of those who choose to use it.

The environment 100 includes a serial number storage 160 for storingserial numbers that are associated (e.g., assigned, attached, etc.) withthe digital currency that exist on any of the DLT networks 102, 104, 106in environment 100.

The communication network 120 is a local area network (LAN), a wide areanetwork (WAN), a personal area network (PAN), or a combination of theseor other networks, that interconnect the electronic computing devices(as discussed herein) and/or databases. The environment 100 may includemany thousands of DLT networks 102, 104, 106; nodes 103, 105, 107;exchange nodes 130; and issuers 140 that are interconnected in anyarrangement to facilitate the exchange of data between such electroniccomputing devices.

FIG. 2A is a block diagram depicting an example exchange node of theenvironment in FIG. 1 , according to some arrangements. While variouscircuits, interfaces, and logic with particular functionality are shown,it should be understood that the exchange node 130 includes any numberof circuits, interfaces, and logic for facilitating the functionsdescribed herein. For example, the activities of multiple circuits maybe combined as a single circuit and implemented on a single processingcircuit (e.g., processing circuit 202A), as additional circuits withadditional functionality are included.

The exchange node 130 includes a processing circuit 202A composed of oneor more processors 203A and a memory 204A. A processor 203A may beimplemented as a general-purpose processor, a microprocessor, anApplication Specific Integrated Circuit (ASIC), one or more FieldProgrammable Gate Arrays (FPGAs), a Digital Signal Processor (DSP), agroup of processing components, or other suitable electronic processingcomponents. In many arrangements, processor 203A may be a multi-coreprocessor or an array (e.g., one or more) of processors.

The memory 204A (e.g., Random Access Memory (RAM), Read-Only Memory(ROM), Non-volatile RAM (NVRAM), Flash Memory, hard disk storage,optical media, etc.) of processing circuit 202A stores data and/orcomputer instructions/code for facilitating at least some of the variousprocesses described herein. The memory 204A includes tangible,non-transient volatile memory, or non-volatile memory. The memory 204Astores programming logic (e.g., instructions/code) that, when executedby the processor 203A, controls the operations of the exchange node 130.In some arrangements, the processor 203A and the memory 204A formvarious processing circuits described with respect to the exchange node130. The instructions include code from any suitable computerprogramming language such as, but not limited to, C, C++, C#, Java,JavaScript, VBScript, Perl, HTML, XML, Python, TCL, and Basic. In somearrangements (referred to as “headless servers”), the exchange node 130may omit the input/output circuit (e.g., input/output circuit 205A), butmay communicate with an electronic computing device via a networkinterface (e.g., network interface 206A).

The exchange node 130 includes a network interface 206A configured toestablish a communication session with a computing device for sendingand receiving data over the communication network 120 to the computingdevice. Accordingly, the network interface 206A includes a cellulartransceiver (supporting cellular standards), a local wireless networktransceiver (supporting 802.11X, ZigBee, Bluetooth, Wi-Fi, or the like),a wired network interface, a combination thereof (e.g., both a cellulartransceiver and a Bluetooth transceiver), and/or the like. In somearrangements, the exchange node 130 includes a plurality of networkinterfaces 206A of different types, allowing for connections to avariety of networks, such as local area networks or wide area networksincluding the Internet, via different sub-networks.

The exchange node 130 includes an input/output circuit 205A configuredto receive user input from and provide information to a user of theexchange node 130. In this regard, the input/output circuit 205A isstructured to exchange data, communications, instructions, etc. with aninput/output component of the exchange node 130. Accordingly,input/output circuit 205A may be any electronic device that conveys datato a user by generating sensory information (e.g., a visualization on adisplay, one or more sounds, tactile feedback, etc.) and/or convertsreceived sensory information from a user into electronic signals (e.g.,a keyboard, a mouse, a pointing device, a touch screen display, amicrophone, etc.). The one or more user interfaces may be internal tothe housing of the exchange node 130, such as a built-in display, touchscreen, microphone, etc., or external to the housing of the exchangenode 130, such as a monitor connected to the exchange node 130, aspeaker connected to the exchange node 130, etc., according to variousarrangements. In some arrangements, the input/output circuit 205Aincludes communication circuitry for facilitating the exchange of data,values, messages, and the like between the input/output device and thecomponents of the exchange node 130. In some arrangements, theinput/output circuit 205A includes machine-readable media forfacilitating the exchange of information between the input/output deviceand the components of the exchange node 130. In still anotherarrangement, the input/output circuit 205A includes any combination ofhardware components (e.g., a touchscreen), communication circuitry, andmachine-readable media.

The exchange node 130 includes a device identification circuit 207A(shown in FIG. 2A as device ID circuit 207A) configured to generateand/or manage a device identifier associated with the exchange node 130.The device identifier may include any type and form of identificationused to distinguish the exchange node 130 from other computing devices.In some arrangements, a device identifier may be associated with one ormore other device identifiers. In some arrangements, to preserveprivacy, the device identifier may be cryptographically generated,encrypted, or otherwise obfuscated by any circuit of the exchange node130. In some arrangements, the exchange node 130 may include the deviceidentifier in any communication (Any of the messages in FIG. 1 , e.g., amonitoring agent setup command, a coin creation command, a lock/unlockcommand, a coin creation command, etc.) that the exchange node 130 sendsto a computing device.

The exchange node 130 includes a digital currency coexistence (DCC)circuit 208A that may be configured to receive, via the communicationnetwork 120, a request from a node (e.g., node 103 a in FIG. 1 ) of a“first” DLT network (e.g., DLT network 102 in FIG. 1 ) to join anexchange network that is managed (hosted) by the exchange node 130. Theexchange network may be an organization of DLT networks, an associationof DLT networks, or a group/collection of DLT networks; where each DLTnetwork is associated with one another by virtue of their membership tothe exchange network. In response to receiving the request, the DCCcircuit 208A may send a message (e.g., “monitoring agent setup command”in FIG. 1 ) to the DLT network 102, where the message causes the DLTnetwork 102 (e.g., one or more nodes of the DLT network 102) toauthorize the exchange node to detect (e.g., monitor) transactionrequests that are associated (e.g., sent by, sent to, or received by)with the DLT network 102. A transaction request may be a request that issent between nodes of a DLT network (e.g., DLT network 102 in FIG. 1 ),or a request that is sent between a node on a first DLT network (e.g.,DLT network 102 in FIG. 1 ) and a node of second DLT network (e.g., DLTnetwork 104 in FIG. 1 ).

In some arrangements, the message includes program code (e.g., a script,an executable) that, when executed by a node of a DLT network, causesthe node to install one or more monitoring agents (e.g., monitoringagent 150 in FIG. 1 ) on any or all of the nodes included in the DLTnetwork to allow the exchange node 130 to detect an occurrence of atransaction request. For example, node 103 a may execute the programcode to install the monitoring agent 150 within its memory (e.g., memory204B) allowing the monitoring agent to detect (e.g., monitor) thecommunication to and/or from its digital currency transaction circuit(e.g., DCT circuit 210B in FIG. 2B) and/or it network interface (e.g.,network interface 206B in FIG. 2B). As another example, node 103 a mayexecute the program code to install one or more monitoring agents formonitoring systems (e.g., subsystems) of an operating system executingon the node 103 a. That is, node 103 a may install a “file systemmonitoring agent” configured to monitor the file system of the operatingsystem for instructions that are sent to and/or by the file system thatare indicative of a transaction request. The node 103 a may install a“network system monitoring agent” configured to monitor the networksystem of the operating system for instructions that are sent to and/orby the network system that are indicative of a transaction request. Thenode 103 a may install a “process system monitoring agent” configured tomonitor the process system of the operating system for instructions thatare sent to and/or by the process system that are indicative of atransaction request. The node 103 a may install a “memory managementsystem monitoring agent” configured to monitor the memory system of theoperating system for instructions that are sent to and/or by the memorysystem that are indicative of a transaction request.

In some arrangements, the message may include program code that, whenexecuted by a node of a DLT network, causes the node to install one ormore “hooks” (not shown in FIG. 1 ) that augment the behavior of anoperating system and/or an application executing on the node tointercept the function calls, messages, and/or events passed betweensoftware components (e.g., a digital wallet) executing on the nodeand/or a transaction ledger (e.g., transaction ledger 218 in FIG. 2B)stored on the node and to redirect the intercepted function calls,messages, and/or events to the exchange node 130. The exchange node 130may then determine if the node has sent and/or received a transactionrequest based on analyzing and/or processing the redirectedcommunication (e.g., the function calls, the messages, and/or theevents). The operating system and/or application executing on the nodemay grant permission for the exchange node 130 to insert the hook intothe operating system and/or application when it sends the join request(shown in FIG. 1 as “join requests”) to the exchange node 130.

In some arrangements, the message (e.g., monitoring agent setup commandin FIG. 1 ) may include a smart contract, that when executed by thenode, causes the node (or the exchange node) of the DLT network tomonitor/detect the transactions that are made by the node. That is, asmart contract is a self-executing contract where the terms andconditions are defined and enforced using software. The node may storethe smart contract on the blockchain. When a transaction request is sentor received by the node on the DLT network, the smart contract mayexecute to notify the exchange node of the transaction request.

The message may cause the node (e.g., node 103 a) to send the message(or copies thereof) to other nodes in the DLT network 102, therebycausing those nodes to also install their own monitoring agent 150 toallow the exchange node to detect (e.g., monitor) their respectivedigital currency transaction circuits. In some arrangements, the messagecauses the node (e.g., node 103 a) to send the message (or copiesthereof) to only the “master nodes” (as discussed herein) that areoperating on the DLT network 102, which in turn, causes the master nodeto install the monitoring agent 150 within the memory (e.g., memory 204Bin FIG. 2B) of the master node. The monitoring agent 150 that isinstalled on the master node allows the exchange node to detect (e.g.,monitor) the communication to and/or from the master node.

The DCC circuit 208A may repeat the joining process for any number ofDLT networks. For example, the DCC circuit 208A may add a “second” DLTnetwork (e.g., DLT network 104) and a “third” DLT network (e.g., DLTnetwork 106), where the one or more nodes of the second and third DLTnetworks install their own monitoring agents 150 to allow the exchangenode 130 to detect (e.g., monitor) communication to and/or from therespective nodes.

The DCC circuit 208A may be configured to create (e.g., mirror) multipletypes of digital currency across the multiple DLT networks that havejoined the exchange network. The DCC circuit 208A creates each digitalcurrency based on the same collateral such that each digital currencysimultaneously represent (e.g., on their respective DLT networks) avalue associated with the same collateral. For example, the exchangenetwork may include DLT network 102 and DLT network 104. As such, theDCC circuit 208A would create, based on the same unit of fiat currency(e.g., fiat currency 142 in FIG. 1 ), a first digital currency of afirst type (e.g., a Bitcoin) on DLT network 102 and a second digitalcurrency of a second type (e.g., an Ether) on DLT network 104. Thus,first digital currency and the second digital currency wouldsimultaneously represent the value associated with the unit of fiatcurrency for at least a period of time. In some arrangements, the firstdigital currency and the second digital currency would equally representthe value associated with the unit of fiat currency. In somearrangements, the first type, the second type, and the third type may bedifferent types of digital currency. In some arrangements, any of thefirst type, the second type, and the third type may be the same type ofdigital currency.

The DCC circuit 208A may be configured to determine the type of digitalcurrency to create for a DLT network by determining a network type thatis associated with a DLT network. For example, the DCC circuit 208A maysend a request to node 103 a of DLT network 102 to request for node 103a to return the network type (e.g., a Bitcoin network, an Ethereumnetwork, a Ripple network, etc.) that is associated with DLT network102. In response, the node 103 a may send the network type to the DCCcircuit 208A. As another example, the DCC circuit 208A may determine thenetwork type that is associated with DLT network 102 by traversingand/or analyzing a node (e.g., node 103 a) of the DLT network to acquire(e.g., gather, collect, etc.) characteristics of the node that indicatethe type of network that the node is operating on and/or operatingwithin.

The DCC circuit 208A may be configured to assign and/or attach a common(“global”) serial number to each of the digital currency (also referredto herein as, “digital coins” or “coins”) that it creates based on thesame collateral to indicate that the digital currency were created fromthe same collateral. For example, the DCC circuit 208A may create adigital currency 110 (e.g., an Ether) on DLT network 102 based on a unitof fiat currency 142 and attach a serial number to the digital currency110. The DCC circuit 208A may then create a digital currency 112 (e.g.,a Bitcoin) on DLT network 104 based on the unit of fiat currency 142 andattach the same serial number to the digital currency 112. In somearrangements, the DCC circuit 208A may generate a serial number that is“unique” by randomly generating the serial number. In some arrangements,a serial number may be unique, in that it is associated with collateral,where no other serial numbers associated with any of the DLT networks102, 104, 106 are associated with the same collateral. In somearrangements, a serial number may be unique in that it is associatedwith only one DLT network. In some arrangements, the DCC circuit 208Amay retrieve the serial number from a database or storage (e.g., serialnumber storage 160 in FIG. 1 ).

The DCC circuit 208A may be configured to store the serial numbers thatit assigns and/or attaches to each of the digital currency in a storage(e.g., serial number storage 160 in FIG. 1 ). The DCC circuit 208 maymaintain, in the storage, a plurality of associations between aplurality of serial numbers and plurality of digital currencies. Eachassociation is a link between a digital currency and the serial numberthat the DCC circuit 208A assigned and/or attached to the digitalcurrency.

The DCC circuit 208A may be configured to detect a transaction requestto transfer a digital currency from a first DLT network to a second DLTnetwork. For example, the node 105 a of DLT network 104 may send atransaction request to node 103 a of DLT network 102 requesting totransfer a digital currency between the DLT networks. If a monitoringagent 150 is installed on node 103 a, then the DCC circuit 208A maydetect the transaction request via the monitoring agent 150 installed onnode 103 a. If a monitoring agent 150 is installed on node 105 a, thenthe DCC circuit 208A may detect the transaction request via themonitoring agent 150 installed on node 105 a. If monitoring agents 150are each installed on node 103 a and node 105 a, then the DCC circuit208A may detect the transaction request via either one or both of themonitoring agents 150.

In some arrangements, a monitoring agent 150 that is installed on a nodeof a DLT network causes the node to intercept the transaction requestand redirect the transaction request to the DCC circuit 208A before thenode 103 a has an opportunity to process the transaction request. Inresponse to receiving the request, the DCC circuit 208A may process(e.g., lock the digital currency 110 onto the DLT network 102) thetransaction request and then send a message (not shown in FIG. 1 ) toallow the node 103 a to process the transaction request that itsrespective monitoring agent 150 intercepted. The message may include thetransaction request (or details thereof) that were originally sent bythe node 105 a to the node 103 a.

In some arrangements, the monitoring agent 150 redirects a copy of thetransaction request to the DCC circuit 208A. In this instance, the node103 a still receives the transaction request that was sent by anothernode 105 a, thereby allowing the node 103 a to process the transactionrequest without having to wait for the DCC circuit 208A to send amessage, as discussed above. As such, the node 103 a and the DCC circuit208A may concurrently process the transaction requests that they eachreceive.

In some arrangements, the DCC circuit 208A may be configured to detect atransaction request to transfer a digital currency from a first DLTnetwork to a second DLT network based on receiving a message from thefirst DLT network and/or the second DLT network. For example, a DLTnetwork that joins the exchange network may enter into an agreement withthe exchange node 130 where the terms (e.g., a set of rules) of theagreement require for the nodes of the DLT network to send theirrespective transaction requests, or the transaction requests that thenodes detect (via any of the techniques discussed here), to the DCCcircuit 208A.

The DCC circuit 208A may be configured to lock, responsive to detectinga transaction request, a digital currency that is identified in thetransaction request onto a DLT network to prevent a transfer of thedigital currency from the DLT network to another DLT network responsiveto receiving a subsequent transaction request. For example, the DCCcircuit 208A may detect that node 103 a of DLT network 102 sent atransaction request to node 105 a of DLT network 104 to transfer thedigital currency 112 (e.g., a Bitcoin) from DLT network 104 to DLTnetwork 102. In response to detecting the transaction request, the DCCcircuit 208A may lock the digital currency 112 onto the DLT network 104.While the digital currency 112 is in a “locked” state, the nodes 105 ofthe DLT network 104 are prevented from transferring the digital currency112 as the result of a subsequent transaction request. That is, asubsequent transaction request that is a transaction request that isdifferent from the transaction request that initially prompted the DCCcircuit 208A to lock the digital currency onto the DLT network.

In some arrangements, the DCC circuit 208A locks the digital currency112 onto the DLT network 104 by encrypting the digital currency using acryptographic algorithm and based on a serial number that is associated(e.g., assigned, attached) with the digital currency to generate alocked digital currency 116. The DCC circuit 208A would then remove thedigital currency 112 from the DLT network 104 such that only the lockeddigital currency 116 remains on the DLT network 104. Thus, a node wouldbe unable to access and/or transfer the locked digital currency 116 fromthe DLT network 104 without being able to identify the locked digitalcurrency 116 on the DLT network 104 and decrypt it. In somearrangements, the DCC circuit 208A prevents the nodes of a DLT networkfrom recording, in their respective electronic transaction ledger (e.g.,transaction ledger 218B in FIG. 2B), the existence of the locked digitalcurrency 116.

The DCC circuit 208A may be configured to send, responsive to locking adigital currency onto the first DLT network, a confirmation request tothe second DLT network, to cause the second DLT network to generate aconfirmation indicating whether the transfer of the digital currencyfrom the first DLT network to the second DLT network has completed. TheDCC circuit 208A may be configured to receive the confirmation from theDLT network. In some arrangements, the confirmation request includes aserial number (e.g., a common serial number, a global serial number)that is associated with the first digital currency. In somearrangements, the confirmation request causes the second DLT network togenerate the confirmation by searching the second DLT network for adigital currency that is associated (e.g., assigned, attached) with theserial number. For example, the DCC circuit 208A may send a confirmationrequest to the DLT network 104 where the confirmation request includes a“first” serial number (e.g., 1007) that is attached to the digitalcurrency 110. In response to receiving the confirmation request, the DLTnetwork 104 may search the electronic transaction ledger (e.g.,transaction ledger 218B in FIG. 2B) of one or more nodes of the DLTnetwork 104 for a digital currency associated with the “first” serialnumber (e.g., 1007), and determine that the digital currency 112 isassociated with a “second” serial (e.g., 1007) that matches the “first”serial number.

The DCC circuit 208A may be configured to determine a presence or anabsence of the second digital currency on the second DLT network. Forexample, the DCC circuit 208A may search the electronic transactionledger (e.g., transaction ledger 218B in FIG. 2B) of one or more nodesof the DLT network 104 for a digital currency associated with the“first” serial number and determine that the digital currency 112 isassociated with a “second” serial number (e.g., 1007) that matches the“first” serial number. In some arrangements, the DCC circuit 208Asearches the electronic transaction ledger of the one or more nodes 105of the DLT network 104 via the one or more monitoring agents 150 thatwere installed on the one or more nodes 105 of the DLT network 104.

In response to determining a presence of the second digital currency(e.g., digital currency 112 in FIG. 1 ) on the second DLT network (e.g.,DLT network 104 in FIG. 1 ), the DCC circuit 208A may destroy the firstdigital currency (e.g., digital currency 110 in FIG. 1 ) on the firstDLT network (e.g., DLT network 102 in FIG. 1 ). In some arrangements,the DCC circuit 208A destroys the first digital currency on the firstDLT network by deleting (e.g., removing) an entry on an electronictransaction ledger (e.g., transaction ledger 218B in FIG. 2B) of a node.In some arrangements, the DCC circuit 208A causes the node to broadcastthe electronic transaction ledger (now updated) to other nodes in theDLT network 102. In some arrangements, the DCC circuit 208A may keep(maintain, preserve, etc.) the first digital currency (e.g., digitalcurrency 110 in FIG. 1 ) locked to the first DLT network (e.g., DLTnetwork 102 in FIG. 1 ) instead of destroying the first digitalcurrency, thereby allowing the second DLT network (e.g., DLT network 104in FIG. 1 ) to transfer the second digital currency (e.g., digitalcurrency 112 in FIG. 1 ) back to the first DLT network if requested viaa second transaction request.

In response to determining an absence of the second digital currency(e.g., digital currency 112 in FIG. 1 ) on the second DLT network (e.g.,DLT network 104 in FIG. 1 ), the DCC circuit 208 A may unlock the firstdigital currency (e.g., digital currency 110) from the first DLT network(e.g., DLT network 102) to allow a transfer of the first digitalcurrency from the first DLT network to another DLT network responsive toreceiving a subsequent transaction request. In some arrangements, theDCC circuit 208A locked the digital currency 110 onto the DLT network102 by encrypting the digital currency 110 using a cryptographicalgorithm and based on the serial number that is associated (e.g.,assigned, attached) with the digital currency 110 to generate a lockeddigital currency (not shown in FIG. 1 ). In this instance, to unlock thelocked digital currency from the DLT network 102, the DCC circuit 208Awould decrypt the locked digital currency using the cryptographicalgorithm and based on the serial number to generate the digitalcurrency 110, which is the unlocked version of the locked digitalcurrency. The DCC circuit 208A would then remove the locked digitalcurrency from the DLT network 102 such that only the digital currency110 remains on the DLT network 102.

The DCC circuit 208A may be configured to send, responsive todetermining the absence, a message to the first DLT network (e.g., DLTnetwork 102) indicating a denial of the transaction request.

The DCC circuit 208A may be configured to receive a request from anadditional DLT network to join the exchange network. In response toreceiving the request, the DCC circuit 208A may send a message to thefirst DLT network, the second message causes the third DLT network toauthorize the one or more processors to monitor transaction requestsassociated with the third DLT network. In response to receiving therequest, the DCC circuit 208 may create, based on the unit of fiatcurrency, a third digital currency (e.g., digital currency 114) of athird type on the third DLT network (e.g., DLT network 106). In somearrangements, the first digital currency, the second digital currency,and the third digital currency simultaneously represent a valueassociated with the unit of fiat currency for at least a period of time.

The exchanges node 130 includes a bus (not shown), such as anaddress/data bus or other communication mechanism for communicatinginformation, which interconnects circuits and/or subsystems of theexchange node 130. In some arrangements, the exchanges node 130 mayinclude one or more of any such circuits and/or subsystems.

In some arrangements, some or all of the circuits of the exchange node130 may be implemented with the processing circuit 202A. For example,the DCC circuit 208A may be implemented as a software application storedwithin the memory 204A and executed by the processor 203A. Accordingly,such arrangement can be implemented with minimal or no additionalhardware costs. In some arrangements, any of these above-recitedcircuits rely on dedicated hardware specifically configured forperforming operations of the circuit.

FIG. 2B is a block diagram depicting an example node of the environmentin FIG. 1 , according to some arrangements. That is, any of the nodes(e.g., nodes 103, 105, 107) in FIG. 1 may be a DLT node 201 in FIG. 2B.While various circuits, interfaces, and logic with particularfunctionality are shown, it should be understood that DLT node 201includes any number of circuits, interfaces, and logic for facilitatingthe functions described herein. For example, the activities of multiplecircuits may be combined as a single circuit and implemented on a singleprocessing circuit (e.g., processing circuit 202B), as additionalcircuits with additional functionality are included.

The DLT node 201 includes a processing circuit 202B composed of one ormore processors 203A and a memory 204B. The processing circuit 202Bincludes identical or nearly identical functionality as processingcircuit 202A in FIG. 2A, but with respect to circuits and/or subsystemsof the DLT node 201 instead of circuits and/or subsystems of theexchange node 130.

The memory 204B (e.g., Random Access Memory (RAM), Read-Only Memory(ROM), Non-volatile RAM (NVRAM), Flash Memory, hard disk storage,optical media, etc.) of processing circuit 202B stores data and/orcomputer instructions/code for facilitating at least some of the variousprocesses described herein. The memory 204B includes identical or nearlyidentical functionality as memory 204A in FIG. 2A, but with respect tocircuits and/or subsystems of the DLT node 201 instead of circuitsand/or subsystems of the exchange node 130.

The DLT node 201 includes a network interface 206B configured toestablish a communication session with a computing device for sendingand receiving data over the communication network 120 to the computingdevice. Accordingly, the network interface 206B includes identical ornearly identical functionality as network interface 206A in FIG. 2A, butwith respect to circuits and/or subsystems of DLT node 201 instead ofcircuits and/or subsystems of the exchange node 130.

The DLT node 201 includes an input/output circuit 205B configured toreceive user input from and provide information to a user. In thisregard, the input/output circuit 205B is structured to exchange data,communications, instructions, etc. with an input/output component of theDLT node 201. The input/output circuit 205B includes identical or nearlyidentical functionality as input/output circuit 205A in FIG. 2A, butwith respect to circuits and/or subsystems of the DLT node 201 insteadof circuits and/or subsystems of the exchange node 130.

The DLT node 201 includes a device identification circuit 207B (shown inFIG. 2B as device ID circuit 207B) configured to generate and/or managea device identifier associated with the DLT node 201. The device IDcircuit 207B includes identical or nearly identical functionality asdevice ID circuit 207A in FIG. 2A, but with respect to circuits and/orsubsystems of the DLT node 201 instead of circuits and/or subsystems ofthe exchange node 130.

The DLT node 201 includes a digital currency transaction (DCT) circuit210B composed of digital currency source code 215B and an electronictransaction ledger (shown in FIG. 1 as, “transaction ledger 218B”). Thedigital currency source code 215B may be stored in memory 204B, whichmay be accessed by and/or run on processor 203B. The transaction ledger218B (shown in FIG. 1 as, “transaction ledger 218B”) may be stored onthe same and/or different processor readable memory, which may beaccessible by processor 203A when running the digital currency sourcecode 215B. In some arrangements, the transaction leger 215B on a firstnode (e.g., node 103 a in FIG. 1 ) of a DLT network corresponds with thetransaction ledger of one or more nodes within the DLT network, to theextent that the nodes have synchronized/updated their electronictransaction ledgers (e.g., received the latest transactions via adownload or during a reconciliation process). Accordingly, theelectronic transaction ledger 115 may be a public ledger.

A DLT node 201 of a “first” DLT network (e.g., DLT network 102 in FIG. 1) may be configured to send, via the communication network 120, arequest to an exchange node (e.g., exchange node 130 in FIG. 1 ) to joinan exchange network that is managed (hosted) by the exchange node 130.

The DLT node 201 may be configured to receive a message from theexchange node 130 that causes the DLT node 201 to authorize the exchangenode 130 to detect (e.g., monitor) transaction requests that areassociated (e.g., sent by, sent to, or received by) with the DLT network102. In some arrangements, the message includes program code (e.g., ascript, an executable) that, when executed by a node of a DLT network,causes the node to install one or more monitoring agents (e.g.,monitoring agent 150 in FIG. 1 ) on any or all of the nodes included inthe DLT network to allow the exchange node 130 to detect an occurrenceof a transaction request.

The message may cause the node (e.g., node 103 a) to send the message(or copies thereof) to other nodes in the DLT network 102, therebycausing those nodes to also install their own monitoring agent 150 toallow the exchange node to detect (e.g., monitor) their respectivedigital currency transaction circuits. In some arrangements, the messagecauses the node (e.g., node 103 a) to send the message (or copiesthereof) to only the “master nodes” (as discussed herein) that areoperating on the DLT network 102, which in turn, causes the master nodeto install the monitoring agent 150 within the memory (e.g., memory 204Bin FIG. 2B) of the master node. The monitoring agent 150 that isinstalled on the master node allows the exchange node to detect (e.g.,monitor) the communication to and/or from the master node.

The DLT node 201 may be configured to receive a message (e.g., coincreation command in FIG. 1 ) causing the DLT node 201 to create adigital currency based on a unit of fiat currency (e.g., fiat currency142 in FIG. 1 ) that is identified in the message.

The DLT node 201 may be configured to receive a request from theexchange node 130 to return the network type (e.g., a Bitcoin network,an Ethereum network, a Ripple network, etc.) that is associated with DLTnetwork of the DLT node 201. In response, the DLT node 201 sends thenetwork type to the exchange node 130.

As discussed herein, the DLT node 201 may be configured to install oneor more monitoring agents (e.g., monitoring agent 150 in FIG. 1 ) withinits memory to allow the monitoring agent to detect an occurrence of atransaction request associated (e.g., sent to, sent by, received by)with the DLT node 201.

In some arrangements, the DLT node 201 may be configured to detect atransaction request by determining that a copy of an electronictransaction ledger that was broadcasted by a neighboring node (e.g.,node 103 b in FIG. 1 ) includes one or more transaction entries that aredifferent than the transaction entries of an electronic transactionledger (e.g., transaction ledger 218B in FIG. 2B) previously stored onthe node. For example, node 103 a of DLT network 102 may receive atransaction request from node 105 a of DLT network 104 to transfer adigital currency 110 (e.g., an Ether) from DLT network 102 to DLTnetwork 104. In response to receiving the transaction request, the DLTnetwork 102 may post (e.g., write, record) the transaction request as anentry on its electronic transaction ledger (e.g., transaction ledger218B on node 103 a) and broadcast a copy of its electronic transactionledger (now updated) to node 103 c in DLT network for validation. Inresponse to receiving the copy of the electronic transaction ledger, thenode 103 c may compare the entries of the received electronictransaction ledger with the transaction entries of its own electronictransaction ledger (e.g., transaction ledger 218B on node 103 c). Thenode 103 c determines that a transaction request occurred if itdetermines, as a result of the comparison, that the electronictransaction ledgers are different. The node then sends a message to theexchange node 130 to indicate that the node detected a transactionrequest, where the message includes the details (e.g., transactingparties, transacting amount, etc.) associated with the transactionrequest.

The DLT node 201 may be configured to receive a message (e.g.,lock/unlock command in FIG. 1 ) from the exchange node 130 to lock adigital currency onto a DLT network to prevent a transfer of the digitalcurrency from the DLT network to another DLT network responsive to asubsequent transaction request. The DLT node 201 may be configured toreceive a message (e.g., lock/unlock command in FIG. 1 ) from theexchange node 130 to unlock the digital currency from the DLT network toallow a transfer of the digital currency from the DLT network to anotherDLT network responsive to the subsequent transaction request.

The DLT node 201 may be configured to receive a confirmation requestfrom the exchange node 130 to return a confirmation indicating whetherthe transfer of the digital currency from the first DLT network to thesecond DLT network has completed. In response to receiving the request,the DLT node 201 determines if the transfer has completed and sends aconfirmation to the exchange node 130 indicating this determination. Insome arrangements, the confirmation request causes the DLT node 201 togenerate the confirmation by searching the DLT network of the DLT node201 for a digital currency that is associated (e.g., assigned, attached)with a “common” or “global” serial number. In some arrangements, the DLTnode 201 may search the electronic transaction ledger (e.g., transactionledger 218B in FIG. 2B) of one or more nodes of the DLT network for adigital currency associated with the serial number.

The DLT node 201 includes a bus (not shown), such as an address/data busor other communication mechanism for communicating information, whichinterconnects circuits and/or subsystems (e.g., digital currencytransaction circuit 210B) of the DLT node 201. In some arrangements, theDLT node 201 may include one or more of any such circuits and/orsubsystems.

In some arrangements, some or all of the circuits of the DLT node 201may be implemented with the processing circuit 202B. For example, any ofthe DLT node 201 may be implemented as a software application storedwithin the memory 204B and executed by the processor 203B. Accordingly,such arrangement can be implemented with minimal or no additionalhardware costs. In some arrangements, any of these above-recitedcircuits rely on dedicated hardware specifically configured forperforming operations of the circuit.

FIG. 3 is a flow diagram depicting a method for preventing thedouble-spending of digital currency that transfers between multiple DLTnetworks from the perspective of an exchange node, according to somearrangements. Additional, fewer, or different operations may beperformed in the method depending on the particular arrangement. In somearrangements, some or all operations of method 300 may be performed byone or more processors executing on one or more computing devices,systems, or servers. In some arrangements, method 300 may be performedby one or more exchange nodes, such as exchange node 130 in FIG. 1 .Each operation may be re-ordered, added, removed, or repeated.

As shown in FIG. 3 , the method 300 includes the operation 302 ofcreating, by one or more processors and based on a unit of fiatcurrency, a first digital currency of a first type on a first DLTnetwork and a second digital currency of a second type on a second DLTnetwork. In some arrangements, each of the first digital currency andthe second digital currency equally represent a value associated withthe unit of fiat currency. The method also includes the operation 304 ofdetecting, by the one or more processors, a transaction request totransfer the first digital currency from the first DLT network to thesecond DLT network. The method also includes the operation 306 oflocking, by the one or more processors responsive to detecting thetransaction request, the first digital currency onto the first DLTnetwork to prevent a transfer of the first digital currency from thefirst DLT network to another DLT network responsive to a subsequenttransaction request.

FIG. 4 is a flow diagram depicting a method for preventing thedouble-spending of digital currency that transfers between multiple DLTnetworks from the perspective of a DLT node, according to somearrangements. Additional, fewer, or different operations may beperformed in the method depending on the particular arrangement. In somearrangements, some or all operations of method 400 may be performed byone or more processors executing on one or more computing devices,systems, or servers. In some arrangements, some or all operations ofmethod 400 may be performed by one or more nodes, such as any of nodes103, 105, 107 in FIG. 1 . Each operation may be re-ordered, added,removed, or repeated.

As shown in FIG. 4 , the method 400 includes the operation 402 ofcreating, by a node of a first DLT network, a first digital currency ofa first type on the first DLT network, the first digital currencyassociated with a second digital currency of a second type on a secondDLT network. In some arrangements, the node of the first DLT networksends a message to the exchange node to notify the exchange node thatthe digital currency have been created on the first DLT network. Themethod also includes the operation 404 of intercepting, by the node ofthe first DLT network, a transaction request to transfer the firstdigital currency from the first DLT network to the second DLT network.The method also includes the operation 406 of locking, by the node ofthe first DLT network responsive to intercepting the transactionrequest, the first digital currency onto the first DLT network toprevent a transfer of the first digital currency from the first DLTnetwork to another DLT network responsive to a second transactionrequest. The method also includes the operation 408 of determining, bythe node of the first DLT network, a presence or an absence of thesecond digital currency on the second DLT network.

The arrangements described herein have been described with reference todrawings. The drawings illustrate certain details of specificarrangements that implement the systems, methods and programs describedherein. However, describing the arrangements with drawings should not beconstrued as imposing on the disclosure any limitations that may bepresent in the drawings.

It should be understood that no claim element herein is to be construedunder the provisions of 35 U.S.C. § 112(f), unless the element isexpressly recited using the phrase “means for.”

As used herein, the term “circuit” may include hardware structured toexecute the functions described herein. In some arrangements, eachrespective “circuit” may include machine-readable media for configuringthe hardware to execute the functions described herein. The circuit maybe embodied as one or more circuitry components including, but notlimited to, processing circuitry, network interfaces, peripheraldevices, input devices, output devices, sensors, etc. In somearrangements, a circuit may take the form of one or more analogcircuits, electronic circuits (e.g., integrated circuits (IC), discretecircuits, system on a chip (SOCs) circuits, etc.), telecommunicationcircuits, hybrid circuits, and any other type of “circuit.” In thisregard, the “circuit” may include any type of component foraccomplishing or facilitating achievement of the operations describedherein. For example, a circuit as described herein may include one ormore transistors, logic gates (e.g., NAND, AND, NOR, OR, XOR, NOT, XNOR,etc.), resistors, multiplexers, registers, capacitors, inductors,diodes, wiring, and so on).

The “circuit” may also include one or more processors communicativelycoupled to one or more memory or memory devices. In this regard, the oneor more processors may execute instructions stored in the memory or mayexecute instructions otherwise accessible to the one or more processors.In some arrangements, the one or more processors may be embodied invarious ways. The one or more processors may be constructed in a mannersufficient to perform at least the operations described herein. In somearrangements, the one or more processors may be shared by multiplecircuits (e.g., circuit A and circuit B may comprise or otherwise sharethe same processor which, in some example arrangements, may executeinstructions stored, or otherwise accessed, via different areas ofmemory). Alternatively or additionally, the one or more processors maybe structured to perform or otherwise execute certain operationsindependent of one or more co-processors. In other example arrangements,two or more processors may be coupled via a bus to enable independent,parallel, pipelined, or multi-threaded instruction execution. Eachprocessor may be implemented as one or more general-purpose processors,application specific integrated circuits (ASICs), field programmablegate arrays (FPGAs), digital signal processors (DSPs), or other suitableelectronic data processing components structured to execute instructionsprovided by memory. The one or more processors may take the form of asingle core processor, multi-core processor (e.g., a dual coreprocessor, triple core processor, quad core processor, etc.),microprocessor, etc. In some arrangements, the one or more processorsmay be external to the apparatus, for example the one or more processorsmay be a remote processor (e.g., a cloud based processor). Alternativelyor additionally, the one or more processors may be internal and/or localto the apparatus. In this regard, a given circuit or components thereofmay be disposed locally (e.g., as part of a local server, a localcomputing system, etc.) or remotely (e.g., as part of a remote serversuch as a cloud based server). To that end, a “circuit” as describedherein may include components that are distributed across one or morelocations.

An exemplary system for implementing the overall system or portions ofthe arrangements might include a general purpose computing computers inthe form of computers, including a processing unit, a system memory, anda system bus that couples various system components including the systemmemory to the processing unit. Each memory device may includenon-transient volatile storage media, non-volatile storage media,non-transitory storage media (e.g., one or more volatile and/ornon-volatile memories), etc. In some arrangements, the non-volatilemedia may take the form of ROM, flash memory (e.g., flash memory such asNAND, 3D NAND, NOR, 3D NOR, etc.), EEPROM, MRAM, magnetic storage, harddiscs, optical discs, etc. In other arrangements, the volatile storagemedia may take the form of RAM, TRAM, ZRAM, etc. Combinations of theabove are also included within the scope of machine-readable media. Inthis regard, machine-executable instructions comprise, for example,instructions and data which cause a general purpose computer, specialpurpose computer, or special purpose processing machines to perform acertain function or group of functions. Each respective memory devicemay be operable to maintain or otherwise store information relating tothe operations performed by one or more associated circuits, includingprocessor instructions and related data (e.g., database components,object code components, script components, etc.), in accordance with theexample arrangements described herein.

It should also be noted that the term “input devices,” as describedherein, may include any type of input device including, but not limitedto, a keyboard, a keypad, a mouse, joystick or other input devicesperforming a similar function. Comparatively, the term “output device,”as described herein, may include any type of output device including,but not limited to, a computer monitor, printer, facsimile machine, orother output devices performing a similar function.

Any foregoing references to currency or funds are intended to includefiat currencies, non-fiat currencies (e.g., precious metals), andmath-based currencies (often referred to as cryptocurrencies). Examplesof math-based currencies include Bitcoin, Ethereum, Litecoin, Dogecoin,and the like.

It should be noted that although the diagrams herein may show a specificorder and composition of method steps, it is understood that the orderof these steps may differ from what is depicted. For example, two ormore steps may be performed concurrently or with partial concurrence.Also, some method steps that are performed as discrete steps may becombined, steps being performed as a combined step may be separated intodiscrete steps, the sequence of certain processes may be reversed orotherwise varied, and the nature or number of discrete processes may bealtered or varied. The order or sequence of any element or apparatus maybe varied or substituted according to alternative arrangements.Accordingly, all such modifications are intended to be included withinthe scope of the present disclosure as defined in the appended claims.Such variations will depend on the machine-readable media and hardwaresystems chosen and on designer choice. It is understood that all suchvariations are within the scope of the disclosure. Likewise, softwareand web implementations of the present disclosure could be accomplishedwith standard programming techniques with rule based logic and otherlogic to accomplish the various database searching steps, correlationsteps, comparison steps and decision steps.

It is also understood that any reference to an element herein using adesignation such as “first,” “second,” and so forth does not generallylimit the quantity or order of those elements. Rather, thesedesignations can be used herein as, a convenient means of distinguishingbetween two or more elements or instances of an element. Thus, areference to first and second elements does not mean that only twoelements can be employed, or that the first element must precede thesecond element in some manner.

The foregoing description of arrangements has been presented forpurposes of illustration and description. It is not intended to beexhaustive or to limit the disclosure to the precise form disclosed, andmodifications and variations are possible in light of the aboveteachings or may be acquired from this disclosure. The arrangements werechosen and described in order to explain the principals of thedisclosure and its practical application to enable one skilled in theart to utilize the various arrangements and with various modificationsas are suited to the particular use contemplated. Other substitutions,modifications, changes and omissions may be made in the design,operating conditions and arrangement of the arrangements withoutdeparting from the scope of the present disclosure as expressed in theappended claims.

What is claimed is:
 1. A method, comprising: creating, by one or moreprocessors and based on a unit of fiat currency, a first digitalcurrency of a first type on a first distributed ledger technology (DLT)network and a second digital currency of a second type on a second DLTnetwork, wherein each of the first digital currency and the seconddigital currency simultaneously represent a value associated with theunit of fiat currency for at least a period of time; detecting, by theone or more processors, a transaction request to transfer the firstdigital currency from the first DLT network to the second DLT network;and locking, by the one or more processors responsive to detecting thetransaction request, the first digital currency onto the first DLTnetwork to prevent a transfer of the first digital currency from thefirst DLT network to another DLT network responsive to a subsequenttransaction request.
 2. The method of claim 1, wherein creating thefirst digital currency and the second digital currency comprises:maintaining, by the one or more processors and in a database, anassociation between a serial number and each of the first digitalcurrency and the second digital currency; and attaching, by the one ormore processors, the serial number to each of the first digital currencyand the second digital currency.
 3. The method of claim 2, furthercomprising: sending, by the one or more processors responsive to lockingthe first digital currency onto the first DLT network, a confirmationrequest to the second DLT network, the confirmation request causing thesecond DLT network to generate a confirmation indicating whether thetransfer of the first digital currency from the first DLT network to thesecond DLT network has completed; and receiving, by the one or moreprocessors, the confirmation from the second DLT network.
 4. The methodof claim 3, wherein the confirmation request comprises the serial numberassociated with the first digital currency and the second digitalcurrency.
 5. The method of claim 3, wherein the confirmation requestcauses the second DLT network to generate the confirmation by searchingthe second DLT network for the second digital currency associated withthe serial number.
 6. The method of claim 2, further comprising:determining, by the one or more processors, a presence or an absence ofthe second digital currency on the second DLT network; and either:destroying, by the one or more processors and responsive to determiningthe presence of the second digital currency on the second DLT network,the first digital currency on the first DLT network; or unlocking, bythe one or more processors and responsive to determining the absence ofthe second digital currency on the second DLT network, the first digitalcurrency from the first DLT network.
 7. The method of claim 6, furthercomprising: sending, by the one or more processors and responsive todetermining the absence of the second digital currency on the second DLTnetwork, a message to the first DLT network indicating a denial of thetransaction request.
 8. The method of claim 1, wherein detecting thetransaction request comprises: receiving, by the one or more processors,the transaction request from the first DLT network or the second DLTnetwork.
 9. The method of claim 1, further comprising: receiving, by theone or more processors and from the first DLT network, a request to joinan exchange network associated with the one or more processors, theexchange network comprising a third DLT network; and sending, by the oneor more processors, a message to the first DLT network, the messagecausing the first DLT network to authorize the one or more processors todetect transaction requests associated with the first DLT network. 10.The method of claim 9, wherein the first DLT network detects thetransaction requests associated with the first DLT network via amonitoring agent that is installed on the first DLT network.
 11. Themethod of claim 9, further comprising: receiving, by the one or moreprocessors and from a third DLT network, a request to join the exchangenetwork associated with the one or more processors; sending, by the oneor more processors, a second message to the third DLT network, thesecond message causing the third DLT network to authorize the one ormore processors to detect transaction requests associated with the thirdDLT network; and creating, by the one or more processors and based onthe unit of fiat currency, a third digital currency of a third type onthe third DLT network, wherein the first digital currency, the seconddigital currency, and the third digital currency simultaneouslyrepresent the value associated with the unit of fiat currency for atleast a period of time.
 12. The method of claim 1, wherein first digitalcurrency of the first type, the second digital currency of the secondtype, and the third digital currency of the third type are differenttypes of digital currency.
 13. A system comprising: one or moreprocessors; and one or more computer-readable storage mediums storinginstructions which, when executed by the one or more processors, causethe one or more processors to: create, based on a unit of fiat currency,a first digital currency of a first type on a first distributed ledgertechnology (DLT) network and a second digital currency of a second typeon a second DLT network, wherein each of the first digital currency andthe second digital currency simultaneously represent a value associatedwith the unit of fiat currency for at least a period of time; detect atransaction request to transfer the first digital currency from thefirst DLT network to the second DLT network; and lock, responsive todetecting the transaction request, the first digital currency onto thefirst DLT network to prevent a transfer of the first digital currencyfrom the first DLT network to another DLT network responsive to asubsequent transaction request.
 14. The system of claim 13, wherein theone or more computer-readable storage mediums store instructions thatcause the one or more processors to further: maintain, in a database, anassociation between a serial number and each of the first digitalcurrency and the second digital currency; and attach the serial numberto each of the first digital currency and the second digital currency.15. The system of claim 14, wherein the one or more computer-readablestorage mediums store instructions that cause the one or more processorsto further: send, responsive to locking the first digital currency ontothe first DLT network, a confirmation request to the second DLT network,the confirmation request causing the second DLT network to generate aconfirmation indicating whether the transfer of the first digitalcurrency from the first DLT network to the second DLT network hascompleted; and receive the confirmation from the second DLT network. 16.The system of claim 15, wherein the confirmation request comprises theserial number associated with the first digital currency and the seconddigital currency.
 17. The system of claim 15, wherein the confirmationrequest causes the second DLT network to generate the confirmation bysearching the second DLT network for the second digital currencyassociated with the serial number.
 18. The system of claim 14, whereinthe one or more computer-readable storage mediums store instructionsthat cause the one or more processors to further: determine a presenceor an absence of the second digital currency on the second DLT network;and either: destroy, responsive to determining the presence of thesecond digital currency on the second DLT network, the first digitalcurrency on the first DLT network; or unlock, responsive to determiningthe absence of the second digital currency on the second DLT network,the first digital currency from the first DLT network.
 19. The system ofclaim 18, wherein the one or more computer-readable storage mediumsstore instructions that cause the one or more processors to further:send, responsive to determining the absence of the second digitalcurrency on the second DLT network, a message to the first DLT networkindicating a denial of the transaction request.
 20. The system of claim13, wherein the one or more computer-readable storage mediums storeinstructions that cause the one or more processors to further: receivethe transaction request from the first DLT network or the second DLTnetwork.
 21. The system of claim 13, wherein the one or morecomputer-readable storage mediums store instructions that cause the oneor more processors to further: receive, from the first DLT network, arequest to join an exchange network associated with the one or moreprocessors, the exchange network comprising a third DLT network; andsend a message to the first DLT network, the message causing the firstDLT network to authorize the one or more processors to detecttransaction requests associated with the first DLT network.
 22. Thesystem of claim 21, wherein the first DLT network detects thetransaction requests associated with the first DLT network via amonitoring agent that is installed on the first DLT network.
 23. Thesystem of claim 21, wherein the one or more computer-readable storagemediums store instructions that cause the one or more processors tofurther: receiving, by the one or more processors and from a third DLTnetwork, a request to join the exchange network associated with the oneor more processors, sending, by the one or more processors, a secondmessage to the third DLT network, the second message causing the thirdDLT network to authorize the one or more processors to detecttransaction requests associated with the third DLT network; andcreating, by the one or more processors and based on the unit of fiatcurrency, a third digital currency of a third type on the third DLTnetwork, wherein the first digital currency, the second digitalcurrency, and the third digital currency simultaneously represent thevalue associated with the unit of fiat currency for at least a period oftime.
 24. The system of claim 13, wherein the first digital currency offirst type, the second digital currency of the second type, and thethird digital currency of the third type are different types of digitalcurrency.
 25. A method, comprising: creating, by a node of a firstdistributed ledger technology (DLT) network, a first digital currency ofa first type on the first DLT network, the first digital currencyassociated with a second digital currency of a second type on a secondDLT network; intercepting, by the node of the first DLT network, atransaction request to transfer the first digital currency from thefirst DLT network to the second DLT network; locking, by the node of thefirst DLT network responsive to intercepting the transaction request,the first digital currency onto the first DLT network to prevent atransfer of the first digital currency from the first DLT network toanother DLT network responsive to a second transaction request; anddetermining, by the node of the first DLT network, a presence or anabsence of the second digital currency on the second DLT network.